A power generation system including a wind power generation apparatus, a solar photovoltaic power generation apparatus, and the like performs power generation by means of renewable energy to output electric power to an electric power system. In such a power generation system, due to natural conditions to change irregularly, the power generation output does not stabilize and fluctuates. That is, a power generation amount sometimes fluctuates greatly. As a result, fluctuations of electric power are sometimes caused in the electric power system to degrade the quality of electric power.
Therefore, it has been proposed that electric power should be stabilized by means of a storage battery to improve the quality of electric power. Concretely, when electric power generated by a power generation device described above is surplus, a storage battery is charged with a surplus, and when it is insufficient, the storage battery is discharged, and thereby fluctuations of electric power are compensated.
However, the storage battery has advantages of good conversion efficiency of electric power and the like, but its aged deterioration caused by repeated charge and discharge needs to be considered, resulting in that a running cost increases due to exchange of batteries. In consideration of such a background, in the power generation system using renewable energy, how effectively generated electric power having large fluctuations is used results in an important factor.
Further, when power generation is performed on a large scale in the power generation system described above, a large-scale storage battery is required, so that a considerable expense is required. Due to such circumstances, it is not easy to smooth power generation output at low cost, and it is sometimes difficult to stabilize electric power.
An object to be solved by the present invention is to provide a power generation system capable of effectively using electric power obtained by wind power generation and capable of easily achieving stabilization of electric power.